The disclosure relates to colorless material with improved antimicrobial performance, and more particularly to paint including quaternary ammonium and a copper-containing glass particles.
Cuprous oxide and metallic copper have been used as an antimicrobial additive in various materials; however, copper is highly colored and may not be used when a white or colorless material is desired. Colorants may be added to adjust the color, but often results in muted colors or a cream or non-white color. Moreover, colorants and other additives may reduce the antimicrobial activity of the material.
Quaternary ammonium has been also been used as an antimicrobial additive in materials such as paint. Paint with low concentrations of quaternary ammonium (e.g., as low as about 0.5%) have exhibited antimicrobial efficacy without impacting the color; however, such paints do not exhibit sufficient antimicrobial efficacy against Staphylococcus aureus, one of the most hardy bacteria commonly found on contaminated surfaces in hospital settings and a very well-known bacteria responsible for hospital-acquired infection (“HAI”). Specifically, such paints exhibit an antimicrobial efficacy of less than 3 log reduction, which is not sufficient for Health Benefit. As used herein, the phrase “Health Benefit” includes materials that exhibit sufficient antimicrobial efficacy to enable the claim of a public health benefit under most government regulatory standards, including under the United States Environmental Protection Agency's Test Method for Efficacy of Copper Alloy as a Sanitizer testing conditions. The United States Environmental Protection Agency (EPA) standard requires a greater than 3 log reduction in Staphylococcus aureus under its Test Method for Efficacy of Copper Alloy as a Sanitizer.
Accordingly, there is a need for a colorless material exhibiting improved antimicrobial efficacy including an efficacy sufficient to impart a Health Benefit.